Good point, there is an acceptance that as long as a device is rechargeable it is 'green', although it may have a net power consumption that would be unacceptable if powered from a primary battery. Transferring these devices' smart power-saving tricks to battery-powered devices might be something we will see, but we need a new, greener primary cell first.
Some fuel cells look interesting there, some claiming to be recyclable.
Professionally, I am concerned about the EMI background noise floor rising at a measurable rate, as you point out.